HCPSS Worthwhile Math Task
Apple Pie Bake Sale
Common Core Standard
7.RP.A.1 Compute unit rates associated with ratios of fractions, including ratios of lengths,
areas and other quantities measured in like or different units. For example, if a person
walks ½ mile in each ¼ hour, compute the unit rate as the complex fraction ½/¼ per
hour, equivalently 2 miles per hour.
MP1:
MP2:
MP3:
MP4:
MP6:
Make sense of problems and persevere in solving them.
Reason abstractly and quantitatively.
Construct viable arguments and critique the reasoning of others.
Model with mathematics.
Attend to precision.
The Task
Recently, a number of tornadoes swept through Oklahoma, causing massive destruction to homes
and property. Your school is having a bake sale in order to raise money for individuals who
have lost their homes. You have volunteered to bake apple pies. Your recipe requires 3 cups of
sliced apples for each pie. You have $25.00 to spend on apples.
As you enter the grocery store, you see that they have three different types of apples that each
can be used to make delicious apple pies. Considering the information listed below, which type
of apple would you choose to buy and why?
Granny Smith
3 apples make 2 cups of slices
Cost = $4.25 a dozen
Gala
1
3 apples make 2 cups of slices
2
Cost = $4.00 a dozen


Macintosh
3
3 apples make 2 cups of slices
4
Cost = $3.25 a dozen
Howard County Public Schools Office of Secondary Mathematics Curricular Projects has
licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0
Unported License.
HCPSS Worthwhile Math Task
Facilitator Notes
1. Introduce the task to the students. Allow students a few minutes to read the task and
begin to develop a strategy for solving. (Look for evidence of MP1.)
2. Provide any materials students request. Ensure that students know what a dozen is.
3. Have students work in pairs or small groups to solve the problem. Have groups record
their strategy. (Look for evidence of MP2 and MP6).
4. As groups work, circulate to monitor what strategies are being used to solve the problem.
Once groups have had an opportunity to solve the task, have groups compare solutions
and strategies (either through a gallery walk, a jigsaw, or through group presentations).
5. Make sure to highlight key strategies, like ratio tables, and how they connect to
determining unit rate and answering the question. (Look for evidence of MP4).
Follow-Up Questions
1. How does the strategy you used compare to the strategies of your classmates? (Look for
evidence of MP3.)
2. If Gala apples are on sale this week for $3.75 a dozen, does this change your
recommendation? Why or why not? (Look for evidence of MP1 and MP6.)
Solutions
Students may use a variety of strategies to find a solution. Here is one possible strategy:
Granny Smith
Dozen
1
2
4
5
5 dozen 9 apples
Groups of 3 Apples
12 / 3 = 4
24 / 3 = 8
48 / 3 = 16
60 / 3 = 20
69/ 3 = 23
Cups of Slices
4x2=8
8 x 2 = 16
16 x 2 = 32
20 x 2 = 40
23 x 2 = 46
Cost
$4.25
$8.50
$17.00
$21.25
$24.40
Pies
8/3=2
16 / 3 = 5
32 / 3 = 10
40 / 3 = 13
46 / 3 = 15
Each apple = 4.25 / 12 = $0.35
5 dozen and 9 apples will make 15 pies with 1/3 cup of slices left over. There is enough money
for an additional apple, but it will not make any extra pies.
Gala
Dozen
2
Groups of 3 ½
Apples
24 / 3 ½ = 6 6/7
Cups of Slices
Cost
Pies
6 6/7 x 2 = 13
5/7
$8.00
(13 5/7) / 3
=4
Howard County Public Schools Office of Secondary Mathematics Curricular Projects has
licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0
Unported License.
HCPSS Worthwhile Math Task
4
48 / 3 ½ = 13 5/7
6
72 / 3 ½ = 20 4/7
6 dozen 2 apples
74 / 3 ½ = 21 1/7
6 dozen 3 apples
75 / 3 ½ = 21 3 / 7
13 5/7 x 2 = 27
2/7
20 4/7 x 2 = 41
1/7
21 1/7 x 2 = 42
2/7
21 3 / 7 x 2 =
42 6/7
$16.00
$24.00
$24.66
$24.99
(27 2/7) / 3
=9
(41 1/7) / 3
= 13
(42 2/7) / 3
= 14
(42 6/7) / 3
= 14
Each apple = 4.00 / 12 = $0.33
6 dozen and 2 apples will give you 14 pies. You can buy another apple, but it will not give you
an extra pie.
Macintosh
Dozen
2
Groups of 3 ¾
Apples
24 / 3 ¾ = 6 2/5
4
48 / 3 ¾ = 12 4/5
7
84 / 3 ¾ = 22 2/5
7 dozen 6 apples
90 / 3 ¾ = 24
Cups of Slices
Cost
Pies
6 2/5 x 2 = 12
4/5
12 4/5 x 2 = 25
3/5
22 2/5 x 2 = 44
4/5
24 x 2 = 48
$6.50
(12 4/5) / 3
=4
(25 3/5) / 3
=8
(44 4/5) / 3
= 14
48 / 3 = 16
$13.00
$22.75
$24.38
Each apple = 3.25 / 12 = $0.27
7 dozen and 6 apples will make 16 pies. You have enough money to buy two more apples, but
that will not be able to make an extra pie.
Choose the Macintosh apples because you can make the most number of pies for the money.
Howard County Public Schools Office of Secondary Mathematics Curricular Projects has
licensed this product under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0
Unported License.